Non-skid underlayment

ABSTRACT

Described are flooring systems which include an underlayment material that has a non-skid surface. The non-skid performance may arise from frictional properties, as opposed to adhesive properties. Such a flooring system may include a top flooring layer, a subfloor, and an underlayment material disposed between the subfloor and the top flooring layer. Methods for a non-skid underlayment are disclosed herein, as well as methods of manufacture. The underlayment material may comprise at least one layer and a non-skid surface for engaging the subfloor, the surface comprising thermoplastic rubber.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of U.S. Provisional PatentApplication No. 62/031,703 filed Jul. 31, 2014, which is incorporated byreference herein as if fully set forth.

BACKGROUND

Flooring systems generally comprise an aesthetic (e.g., decorative) topflooring layer installed over a structural substrate (commonly referredto as a subfloor). An underlayment layer may be interposed between thetop flooring layer and the substrate for purposes of sound reduction,cushioning, moisture barrier, and/or protection.

The top flooring layer must be installed on a flat, level, substrate forboth structural and aesthetic reasons. For example, any bumps orirregularities in the substrate may be visible to the consumer, which isnot aesthetically pleasing. Moreover, beyond undesirable lightreflection and other cosmetic drawbacks, top flooring layers aregenerally fragile enough that such irregularities eventually lead totransfer through to the top layer, increased wear, cracking, or otherdamage. In cases of interlocking top flooring layer components (e.g.,laminate flooring, engineered flooring), irregularities in the substratemay prevent proper mechanical interaction, thereby undermining theintegrity of the top flooring layer and creating unsightly gaps or eventrip hazards.

One type of irregularity in a flooring system can result from theunderlayment slipping or bunching to create wrinkles during installationof the underlayment, or more often, during installation of the topflooring layer. For example, in some installations, components of thetop flooring layer are slid into place. If the friction between the topflooring layer component and the underlayment is greater than thefriction between the underlayment and the substrate, the underlaymentmay bunch. Therefore, better systems, methods, and non-skid compositionsare needed.

SUMMARY

A flooring system as disclosed herein may include an underlaymentmaterial that has a non-skid surface. The non-skid performance may arisefrom frictional properties, as opposed to adhesive properties. Such aflooring system may include a top flooring layer, a subfloor, and anunderlayment material disposed between the subfloor and the top flooringlayer. Methods for a non-skid underlayment are disclosed herein, as wellas methods of manufacture. The underlayment material may comprise atleast one layer having a non-skid surface for engaging the subfloor, thesurface comprising thermoplastic rubber.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 depicts a top perspective sectional view of a flooring systemhaving a non-skid underlayment material.

FIG. 2 depicts a cross-sectional view of a flooring system having anon-skid underlayment material.

FIG. 3 depicts a cross-sectional view of a non-skid underlaymentmaterial.

FIG. 4 depicts a bottom perspective sectional view of a non-skidunderlayment material.

FIG. 5 depicts a cross-sectional view of a non-skid underlaymentmaterial.

FIG. 6 depicts a cross-sectional view of a non-skid underlaymentmaterial.

FIG. 7 is a diagram of a method for manufacturing a non-skidunderlayment material.

DETAILED DESCRIPTION

FIG. 1 illustrates a flooring system 100. The flooring system 100 may beused in a commercial or residential setting. The flooring system 100 mayinclude a top flooring layer 102, which may also be referred to asflooring. The top flooring layer 102 may be mainly for decorativepurposes. Examples of top flooring layers 102 include carpet, tile,sheet vinyl, luxury vinyl tile (or planks), solid hardwood, engineeredwood, and laminate flooring.

The flooring system 100 may include a subfloor 104. The term “subfloor”refers to the structural substrate above which a top flooring layer 102is installed. Examples of subfloors 104 include concrete, plywood,oriented strand board (OSB), composite wood, and in some cases, existingvinyl or hardwood flooring. Often, the subfloor 104 may contain multipleirregularities in its surface. For example, the subfloor 104 may includea depression 106. The depression 106 may be a dimple, a gouge, or a lowspot. The subfloor 104 may include projections from its surface such asa bump (e.g., a high spot) 108, or in cases where the subfloor is ofplywood, oriented strand board (OSB), or composite wood, a projectingnail head 110. The subfloor may have a multiplicity of irregularities ofdiffering heights and depths. For example, in concrete subfloors, bothhigh spots and low spots are fairly typical.

The flooring system may include a non-skid underlayment material 120interposed between the top flooring layer 102 and subfloor 104. Theunderlayment material 120 may have greater frictional properties withrespect to the subfloor 104 than its frictional properties with respectto the top flooring layer 102, as will be described. The flooring system100 may have additional layers (not depicted).

The top flooring layer 102, underlayment material 120, and subfloor 104,may be assembled by any practicable means. The underlayment material 120may be laid on the subfloor 104 and the top flooring layer 102 laid uponthe underlayment material without affixing them to each other (e.g., afloating installation method). The underlayment material 120 may beglued to the subfloor 104 with adhesive and the top flooring layer 102glued to the underlayment material with adhesive (e.g., a double gluedown installation). One layer of the top flooring layer 102,underlayment material 120, and subfloor 104 may be glued to its adjacentlayer with adhesive without affixing the top flooring layer to thesubfloor (e.g., a single glue down installation). Similarly, one layerof the top flooring layer 102, underlayment material 120, and subfloor104 may nailed or tacked to another layer, or both. Examples of nailingand/or tacking installations include carpet installation and hardwoodflooring installation over a wood-based subfloor. Advantages of theunderlayment material 120 for a floating installation in particular willbe described.

Turning to FIG. 2, a cross section of a flooring system 200 is depicted.The flooring system 200 may be used in a commercial or residentialsetting. The flooring system 200 may include a top flooring layer 202,which may be carpet, tile, sheet vinyl, luxury vinyl tile (or planks),solid hardwood, engineered wood, and laminate flooring.

The flooring system 200 may include a subfloor 204 similar to thatdescribed in FIG. 1.

The flooring system 200 may include a non-skid underlayment material 220interposed between the top flooring layer 202 and subfloor 204. Theunderlayment material 220 may have greater frictional properties withrespect to the subfloor 204 than its frictional properties with respectto the top flooring layer 202. The underlayment material 220 may belightweight and easy to handle.

The flooring system 200 may include an optional vapor barrier layer 230.As described in detail herein with respect to FIG. 3, the underlaymentmaterial 220 itself may have moisture vapor transmission properties thatare suitable for certain applications. In some applications, however,additional moisture vapor protection may be desirable. If desired, avapor barrier layer 230 may be disposed between the top flooring layer202 and the subfloor 204. The vapor barrier layer 230 may be a film,which may be a polypropylene film, or a polyethylene film, or a foil,disposed between the underlayment material 220 and the subfloor 204. Thevapor barrier layer 230 may be adhered to the underlayment material 220and/or to the subfloor 204. The flooring system 200 may be assembled byany practicable means, generally depending on the type of subfloor 204and top flooring layer 202.

Turning to FIG. 3, a cross section of a non-skid underlayment material320 which can be used in the flooring systems of FIG. 1 and/or FIG. 2 isdepicted. The underlayment material 320 may have at least two layers ofdistinct composition and/or mechanical properties, and may be abilaminate (as illustrated). The underlayment material 320 may haveadditional layers (not depicted). The underlayment material 320 may be asingle layer (such as depicted in FIGS. 5 and 6).

The underlayment material 320 may comprise a first layer 322. In aflooring system, the layer 322 may be adjacent to a top flooring layer(not depicted).

The layer 322 may comprise a fiber (such as a non-woven), a film (suchas a thermoplastic polyolefin film, a PVC film, an EVA film, a vinylfilm, or other membrane), a foil (such as a metallic foil), or a foam(such as a memory foam, polyurethane foam, EVA foam, PVC foam, latexfoam, or a polyolefin foam). The layer 322 may comprise polyethylene,may consist essentially of polyethylene, or may consist essentially of apolyethylene foam. The layer 322 may comprise a non-cross-linked foam.The layer 322 may comprise a memory foam. The layer 322 may comprisenon-cross-linked polyethylene. The layer 322 may have a density lessthan about 25 kg/m3. The layer 322 may have a density less than about 20kg/m3. The layer 322 may have a density selected to compress underloading. The layer 322 may have a 25% compressive strength of less thanabout 1 kg/cm2 as measured by JIS K6767. The layer 322 may have a 25%compressive strength of less than about 0.8 kg/cm2 as measured by JISK6767. The layer 322 may contribute to the SLP and MVTR of theunderlayment material 320.

The layer 322 may be a non-woven fiber.

The layer 322 may have a thickness in a range from about 0.5 mm to about6.0 mm. The thickness of the layer 322 may be in a range from about 1.5mm to about 2.5 mm.

The underlayment material 320 may comprise a second layer 324 affixed tothe layer 322. The layer 322 may be laminated to the layer 324 at theinterface of their surfaces. Alternatively, the layer 322 may beconnected to the layer 324 by any known means (e.g., mechanical).

The layer 324 may comprise a fiber (such as a non-woven), a film (suchas a thermoplastic polyolefin film, a PVC film, an EVA film, a vinylfilm, or other membrane), a foil (such as a metallic foil), or a foam(such as a memory foam, polyurethane foam, EVA foam, PVC foam, latexfoam, or a polyolefin foam).

The layer 324 may comprise a cross-linked polypropylene copolymer (EPC)and a linear low density/polyethylene (LLDPE) blend foam with an EPCcontent of about 20% to 90% by weight. Preferably, the EPC content isbetween 50% and 90%. More preferably, the EPC content is between 70% and90%. Other olefin materials that are suitable for use include, forexample, homopolymers and copolymers of polyethylene, includinghigh-density polyethylene (HDPE), low-density polyethylene (LDPE),very-low-density polyethylene (VLDPE), ultra-low-density polyethylene(ULDPE), and polymers or copolymers of polypropylenes, includingcross-linked ethylene propylene copolymer.

The layer 324 may comprise a foam underlayment material such as, theFLOORMUFFLER™ underlayment available from Diversified Foam Products,Inc. (www.floormuffler.com).

The layer 324 may have a 25% compressive strength of at least about 0.85kg/cm2, as measured by JIS K6767. Preferably, the layer 324 has a 25%compressive strength of at least about 1.0 kg/cm2. More preferably, thelayer 324 has a 25% compressive strength of at least about 1.2 kg/cm2.Compressive strength is a property of the foam structure obtainedprimarily by the selection of resin, foam density, and the manufacturingprocesses used to convert resin into foam. It should be understood thathigher polypropylene content may produce higher compressive strengthand, accordingly, lower average reflected SPL. Density may also be afactor. For example, to increase compressive strength from approximately3 kg/cm2 to approximately 6 kg/cm2, the foam density may be increasedfrom about 100 kg/m3 to about 121 kg/m3.

The layer 324 may contribute reduced moisture vapor transmission rates(MVTR) to the underlayment material 320 without the need for theadditional barrier layers. The layer 324 may have a MVTR of <3.0 lb/1000ft²/24 hr. Flooring industry standards for MVTR of less than 3.0 lb/1000ft²/24 hr are typically achieved by adding additional vapor barrierlayers that add to both product cost and weight.

The layer 324 may contribute a desirable reflected sound pressure level(SPL) to the underlayment material 320. SPL varies with foamcomposition, extent of cross-linking, density, and thickness. The layer324 may have a polypropylene content of greater than about 60% togreater than about 90%. The layer 324 may have a cross-link percentageor cross-link level that may range from about 40% to about 80%. Highercross-link levels are possible; however, if cross-linking is too high,the foam will be difficult to roll onto a core, and will be difficult tolay flat. The type of resins selected, the amount of chemicalcross-linking agent used, and the amount of exposure to a radiationsource, such as an electron beam irradiation device, dictate the degreeof cross-linking Also, in general, higher cross-link percentage providesslightly higher compressive strength. It is expected, therefore, thathigher cross-link percentage should lead to slightly lower reflected SPLfor the layer 324. It is also expected that higher cross-link percentageshould also lead to lower MVTR.

The density of the layer 324 as determined by method ASTM D3575, may beabout 20 to about 200 kg/m3. The layer 324 may have a range of densityfrom about 40 to about 100 kg/m3. The layer 324 may have a range ofdensity from about 50 to about 60 kg/m3. Higher density tends toincrease the compressive strength of the foam and thereby reduce thereflected SPL. Increasing foam density, however, tends to add to productcost due to increased raw material consumption to manufacture. Densitymay be controlled by a number of factors, the types of resins used, thedegree of cross-linking, process conditions, and the type and amount offoaming agent used. The thickness of the layer 324 may be in a rangefrom about 0.5 mm to about 6.0 mm. The thickness of the layer 324 may bein a range from about 1.5 mm to about 2.5 mm. Thickness is dictated bythe resin selection, type and amount of chemical foaming agent used,extruded sheet thickness, tension during the foaming operation, and theamount of heat applied during the conversion of sheet into foam. A 100ft² roll of layer 324 may weigh less than about 5 lbs, while providinglow reflected sound pressure levels in the 300 Hz to 1000 Hz range andMVTR performance that meets flooring industry standards.

The layer 324 has a surface 326. The surface 326 provides non-skidproperties to the underlayment material 320. The surface 326 may providenon-skid properties to the underlayment material 320 without impartingadhesive properties. The surface 326 may comprise thermoplastic rubber.The surface 326 may comprise a melt-process-able rubber. The surface 326may be a natural rubber, a thermoplastic urethane, a styrene-butadienerubber, a styrene ethylene butylene styrene block copolymer, an ethylenepropylene diene monomer rubber, a nitrile rubber, or a blend of any ofthese, with or without a thermoplastic rubber.

The surface 326 may comprise polypropylene or polyethylene.

The surface 326 may comprise a cling foam, such as an emulsion clingfoam, a PVC foam plastisol, a highly plasticized PVC solid, an ethylenevinyl acetate, an acrylic, polyethylene, or polyurethane foam or solid,or any polymer that can be formed with frictional, but not tacky,properties (e.g., frictional properties, as opposed to adhesiveproperties).

The surface 326 may be formed as a coating.

The surface 326 may be formed by laminating a layer comprising thematerial that comprises the surface to the layer 324.

The surface 326 may describe the boundary (e.g., the physical exterior)of the layer 324. For example, the surface 326 may be formed bydispersing the material comprising the surface throughout the layer 324,such that the face of the layer 324 is a surface with non-skidproperties.

The underlayment material 320 may comprise additional layers. Forexample, a vapor barrier polypropylene film or polyethylene film may beadhered to the underlayment material 320 before the underlayment isrolled (as described below). Thus, the underlayment material 320 may bedelivered to the point of installation with the optional vapor barrieralready adhered thereto, thus simplifying installation of theunderlayment material and vapor barrier.

The underlayment material 320 may include non-skid elements affixed,adhered to, or resulting from, the layer 322, layer 324, or both.

The underlayment material 320 may include a foil layer to reflect heat.

The underlayment material 320 may include means to adhere adjoiningsections of underlayment. The underlayment material 320 may include atape strip (not depicted) to facilitate installation. The underlaymentmaterial 320 may comprise a first roll (not depicted) having a tapestrip on a first planar surface of the underlayment, and a pull-out lip(not depicted) on the first planar surface, axial to the tape strip,such that when the first roll is unrolled and laid out next to a secondroll that has also been unrolled and laid out, the tape strip of thefirst roll will engage the lip of the second roll, thereby connectingthe first and second rolls. This may include creating a moistureresistant engagement between the tape strip and the lip (e.g., sealingwhat otherwise may be a vapor gap between two adjacent underlaymentsections). The lip may extend axially from the roll in a range fromabout 0.5 in to about 8 in. The lip may be formed from a layer affixedto the underlayment 320 that extends axially fully across the roll, ormay be a strip.

The underlayment material 320 may include at least one of ananti-microbial additive, a flame retardant additive, and an adhesionpromoter.

The underlayment material 320 may be embossed or de-bossed forlamination, traction, or alignment purposes. The underlayment material320 may receive printed materials, such as instructions, trademarks, orother communications.

The underlayment material 320 may have an Impact Insulation Class (IIC)value greater than about 40, greater than about 50, and/or greater thanabout 55, but less than about 80.

The thickness of the underlayment material 320 may be in a range fromabout 1 mm to about 15 mm. The thickness of the underlayment material320 may be in a range from about 3 mm to about 10 mm. Relatively thicklayers of around 6.0 millimeters or more may interfere with wall moldingor door clearances. The thickness of the underlayment material 320 maybe in a range from about 4 mm to about 6 mm.

Turning to FIG. 4, a bottom perspective sectional view of a non-skidunderlayment material 420 which can be used in the flooring systems ofFIG. 1 and/or FIG. 2 is depicted. The underlayment material 420 may haveat least two layers of distinct composition and/or mechanicalproperties, and may be a bilaminate (as illustrated). The underlaymentmaterial 420 may have additional layers (not depicted). The underlaymentmaterial 420 may be a single layer (such as depicted in FIGS. 5 and 6).

The underlayment material 420 may comprise a first layer 422 and asecond layer 424. In a flooring system, the layer 422 may be adjacent toa top flooring layer (not depicted).

As discussed above, the layer 422 and the layer 424 may comprise a fiber(such as a non-woven), a film (such as a thermoplastic polyolefin film,a PVC film, an EVA film, a vinyl film, or other membrane), a foil (suchas a metallic foil), or a foam (such as a memory foam, polyurethanefoam, EVA foam, PVC foam, latex foam, or a polyolefin foam), providedthat the layers have distinct compositional differences and/ordifferences in mechanical properties.

A surface 426 is disposed upon at least a portion of the layer 424. Thesurface 426 may be applied to the surface of the underlayment 420 whichcontacts the subfloor. The surface 426 provides non-skid properties tothe underlayment material 420. The surface 426 may provide non-skidproperties to the underlayment material 420 without imparting adhesiveproperties. The surface 426 may comprise thermoplastic rubber. Thesurface 426 may comprise a melt-process-able rubber. The surface 426 maycomprise a natural rubber, a thermoplastic urethane, a styrene-butadienerubber, a styrene ethylene butylene styrene block copolymer, an ethylenepropylene diene monomer rubber, a nitrile rubber, or a blend of any ofthese, with or without a thermoplastic rubber.

The surface 426 may comprise polypropylene or polyethylene.

The surface 426 may comprise a cling foam, such as an emulsion clingfoam, a PVC foam plastisol, a highly plasticized PVC solid, an ethylenevinyl acetate, an acrylic, polyethylene, or polyurethane foam or solid,or any polymer that can be formed with frictional, but not tacky,properties (e.g., frictional properties, as opposed to adhesiveproperties).

The surface 426 may be formed as a coating.

The surface 426 may be formed by laminating a layer comprising thematerial that comprises the surface to the layer 424.

The surface 426 may describe the boundary (e.g., the physical exterior)of the layer 424. For example, the surface 426 may be formed bydispersing the material comprising the surface throughout the layer 424,such that the face of the layer 424 is a surface with non-skidproperties.

Recessed features 428 may be disposed in the layer 424, such as may becreated by de-bossing. The recessed features 428 may balance against thenon-skid effects of the surface 426, by reducing surface area of layer424 that contacts the subfloor (not depicted). The features 428 may beabsent in some embodiments. Additional embossed features or textures(not depicted) may be present.

Turning to FIG. 5, a sectional view of a non-skid underlayment material520 which comprises a single layer 524 is depicted. The underlaymentmaterial 520 can be used in the flooring systems of FIG. 1 and/or FIG.2. The underlayment material 520 may have additional layers (notdepicted).

The layer 524 may comprise a fiber (such as a non-woven), a film (suchas a thermoplastic polyolefin film, a PVC film, an EVA film, a vinylfilm, or other membrane), a foil (such as a metallic foil), or a foam(such as a memory foam, polyurethane foam, EVA foam, PVC foam, latexfoam, or a polyolefin foam). The layer 524 may comprise a cross-linkedpolypropylene copolymer (EPC) and a linear low density/polyethylene(LLDPE) blend foam with an EPC content of about 20% to 90% by weight.Preferably, the EPC content is between 50% and 90%. More preferably, theEPC content is between 70% and 90%. Other olefin materials that aresuitable for use include, for example, homopolymers and copolymers ofpolyethylene, including high-density polyethylene (HDPE), low-densitypolyethylene (LDPE), very-low-density polyethylene (VLDPE),ultra-low-density polyethylene (ULDPE), and polymers or copolymers ofpolypropylenes, including cross-linked ethylene propylene copolymer.

The layer 524 may comprise a foam underlayment material such as, theFLOORMUFFLER^(TM) underlayment available from Diversified Foam Products,Inc. (www.floormuffler.com).

A surface 526 is applied to at least a portion of the layer 524. Thesurface 526 provides non-skid properties to the underlayment material520. The surface 526 may provide non-skid properties to the underlaymentmaterial 520 without imparting adhesive properties. The surface 526 maycomprise thermoplastic rubber. The surface 526 may comprise amelt-process-able rubber. The surface 526 may comprise a natural rubber,a thermoplastic urethane, a styrene-butadiene rubber, a styrene ethylenebutylene styrene block copolymer, an ethylene propylene diene monomerrubber, a nitrile rubber, or a blend of any of these, with or without athermoplastic rubber.

The surface 526 may comprise polypropylene or polyethylene.

The surface 526 may comprise a cling foam, such as an emulsion clingfoam, a PVC foam plastisol, a highly plasticized PVC solid, an ethylenevinyl acetate, an acrylic, polyethylene, or polyurethane foam or solid,or any polymer that can be formed with frictional, but not tacky,properties (e.g., frictional properties, as opposed to adhesiveproperties).

The surface 526 may be formed as a coating.

The surface 526 may be formed by laminating a layer comprising thematerial that comprises the surface to the layer 524.

The surface 526 may describe the boundary (e.g., the physical exterior)of the layer 524. For example, the surface 526 may be formed bydispersing the material comprising the surface throughout the layer 524,such that the face of the layer 524 is a surface with non-skidproperties.

Turning to FIG. 6, a non-skid underlayment material 620 which comprisesa single layer 624 is depicted. The underlayment material 620 can beused in the flooring systems of FIG. 1 and/or FIG. 2. The underlaymentmaterial 620 may have additional layers (not depicted).

The layer 624 may comprise a fiber (such as a non-woven), a film (suchas a thermoplastic polyolefin film, a PVC film, an EVA film, a vinylfilm, or other membrane), a foil (such as a metallic foil), or a foam(such as a memory foam, polyurethane foam, EVA foam, PVC foam, latexfoam, or a polyolefin foam). The layer 624 may comprise a cross-linkedpolypropylene copolymer (EPC) and a linear low density/polyethylene(LLDPE) blend foam with an EPC content of about 20% to 90% by weight.Preferably, the EPC content is between 50% and 90%. More preferably, theEPC content is between 70% and 90%. Other olefin materials that aresuitable for use include, for example, homopolymers and copolymers ofpolyethylene, including high-density polyethylene (HDPE), low-densitypolyethylene (LDPE), very-low-density polyethylene (VLDPE),ultra-low-density polyethylene (ULDPE), and polymers or copolymers ofpolypropylenes, including cross-linked ethylene propylene copolymer.

The layer 624 may comprise a foam underlayment material such as, theFLOORMUFFLER™ underlayment available from Diversified Foam Products,Inc. (www.floormuffler.com).

The layer 624 has a pair of surfaces 626. The surface 626 providesnon-skid properties to the underlayment material 620 on both surfaces(such as the surface contacting the subfloor and the surface contactingthe top flooring layer). The surface 626 may provide non-skid propertiesto the underlayment material 620 without imparting adhesive properties.The surface 626 may comprise thermoplastic rubber. The surface 626 maycomprise a melt-process-able rubber. The surface 626 may be a naturalrubber, a thermoplastic urethane, a styrene-butadiene rubber, a styreneethylene butylene styrene block copolymer, an ethylene propylene dienemonomer rubber, a nitrile rubber, or a blend of any of these, with orwithout a thermoplastic rubber.

The surface 626 may comprise polypropylene or polyethylene.

The surface 626 may comprise a cling foam, such as an emulsion clingfoam, a PVC foam plastisol, a highly plasticized PVC solid, an ethylenevinyl acetate, an acrylic, polyethylene, or polyurethane foam or solid,or any polymer that can be formed with frictional, but not tacky,properties (e.g., frictional properties, as opposed to adhesiveproperties).

The surface 626 may be formed as a coating.

The surface 626 may be formed by laminating a layer comprising thematerial that comprises the surface to the layer 624.

The surface 626 may describe the boundary (e.g., the physical exterior)of the layer 624. For example, the surface 626 may be formed bydispersing the material comprising the surface throughout the layer 624,such that the face of the layer 624 is a surface with non-skidproperties.

FIG. 7 provides a flowchart of an example method 700 for manufacturing apolyolefin foam underlayment material. At 702, one or more polyolefinresins may be mixed with a foaming agent, one or more cross-linkingagents, and/or one or more additives, into a homogenous mixture.Examples of polyolefin resins include polyethylene and/or polypropylene.Examples of cross-linking agents include peroxides (e.g., di cumylperoxide, etc.) for polyethylenes, and di vinyl benzene forpolypropylenes. Examples of additives include flame retardants, adhesionpromoters, colorants, and anti-microbial agents. A homogenous mixturemay be achieved by spinning the mixture in a mechanical mixer designedfor compounding plastic resins. Examples of such mixers are well-known.To ensure complete and proper mixing, agitation rate, temperature, andprocessing duration may be selectively controlled during this step bywell-known industrial process control means.

At 704, the mixture may charged, for example, into a conventionalplastics extruder, into which the ingredients are conveyed in a barrelby a screw, to produce a solid, thin, plastic web. The ingredients maybe initially compressed and mixed as the materials move along the screw.

Heater elements, along with the shearing action of materials againsteach other and the screw and barrel, cause the resins to melt into aviscous liquid state. Additives and/or colorants may be added to theproduct at this stage of the process as well. The screw pushes themelted extrudate through a die opening to produce the thin, solid web.The web may typically be between about 0.2 and about 3.0 millimeters inthickness, although not limited, as thicker or thinner webs can beproduced as desired. As it is extruded, the web may cool from a moltenstate to a solid state. The web may then be trimmed, and wound into aroll.

At 706, the polymer resins may be cross-linked, for example byirradiation by electron beam. Other methods, such as chemicalcross-linking, for example, may be employed. The degree of cross-linkingmay be controlled to result in a typical cross-link density of about 15%to about 80%. A higher percentage level of cross-linking is possible ifdesired. A desired degree of cross-linking may be achieved by the typeof resins selected, the amount of chemical cross-linking agent used,and/or the exposure to a radiation source such as an electron beamirradiation device.

At 708, the continuous polymer web may be converted into a relativelylow-density foam. For example, the foam may be heated by radiantheaters, molten salt, hot air, or other heating devices. The heat causesa reaction of the chemical foaming agent that causes the foaming agentto releases gases, thus forming a cellular structure in the web. Thecombination of resins selected, cross-linking, and the process used maybe selected to create a fine-celled structure, with typical cellsranging from about 0.1 to about 1.0 millimeter. It should be understoodthat larger and smaller cell sizes are possible.

A desired thickness may be achieved by the resin selection, type andamount of chemical foaming agent used, extruded sheet thickness, tensionduring the foaming operation, amount of heat applied during theconversion of sheet into foam. For example, an extruded sheet having athickness of about 1 millimeter may produce a relatively high densitypolyolefin foam having a thickness of about 1.5 millimeter if littlefoaming agent is used. A relatively low density foam having a thicknessof about 2.5 millimeter may be produced if a greater quantity of foamingagent is used. A desired density may be achieved by the selection ofresins used, the degree of cross-linking, process conditions, and thetype and amount of foaming agent used.

The continuous polymer web may be converted into a relativelylow-density foam. For example, the foam may be heated by radiantheaters, molten salt, hot air, or other heating devices. The heat causesa reaction of the chemical foaming agent that causes the foaming agentto releases gases, thus forming a cellular structure in the web.

A desired thickness may be achieved by the resin selection, type andamount of chemical foaming agent used, extruded sheet thickness, tensionduring the foaming operation, amount of heat applied during theconversion of sheet into foam. For example, an extruded sheet having athickness of about 1 millimeter may produce a relatively high densitypolyolefin foam having a thickness of about 1.5 millimeter if littlefoaming agent is used. A relatively low density foam having a thicknessof about 2.5 millimeter may be produced if a greater quantity of foamingagent is used. A desired density may be achieved by the selection ofresins used, process conditions, and the type and amount of foamingagent used. The layer may be laminated to another layer (see FIG. 3).

At 710, at least one layer is provided (e.g., at least partiallyprovided with) with a surface as described herein to provide non-skidproperties to the underlayment material.

At 712, the finished foam web may be rolled onto a core, such as acardboard or paper tube, for example.

At 714, the finished foam web may undergo further processing, forexample, the foam web may be coated with an adhesive layer or releaselayer, laminated with films (including, for example, lips and tapestrips as described above), foils, fabrics, nonwovens, or other foams,or molded for any of a variety of uses.

In another method, the underlayment material may be a lamination of afoam to a coated film (e.g., polyethylene, polypropylene, or otherscoated with the thermoplastic rubber) to provide a non-skid surface. Forexample, the film may be coated, and then the film could be laminated tothe foam.

1. A flooring system, comprising: a top flooring layer; a subfloor; andan underlayment material disposed between the subfloor and the topflooring layer, wherein the underlayment material comprises: at leastone layer; and a non-skid surface disposed on the layer for engaging thesubfloor, the surface comprising thermoplastic rubber.
 2. The flooringsystem of claim 1, wherein the layer of the underlayment material is across-linked polyolefin foam.
 3. The flooring system of claim 2, whereinthe cross-linked polyolefin foam is produced from a resin compositioncomprising a blend of polyethylene and polypropylene.
 4. The flooringsystem of claim 1, wherein the layer of the underlayment material is anon-cross-linked foam.
 5. The flooring system of claim 4, wherein thenon-cross-linked foam is a polyolefin foam.
 6. The flooring system ofclaim 4, wherein the non-cross-linked foam consists essentially ofpolyethylene.
 7. The flooring system of claim 1, further comprising anon-woven layer laminated to the layer of the underlayment material. 8.The flooring system of claim 1, wherein the surface is on both surfacesof the underlayment material.
 9. A flooring system, comprising: a topflooring layer; a subfloor; and an underlayment material disposedbetween the subfloor and the top flooring layer, wherein theunderlayment material comprises: at least one polyolefin layer; anon-woven layer; and a non-skid surface disposed on the polyolefin layerfor engaging the subfloor, the surface comprising thermoplastic rubber.10. The flooring system of claim 9, wherein the at least one polyolefinlayer is a cross-linked polyolefin foam.
 11. The flooring system ofclaim 10, wherein the cross-linked polyolefin foam comprises a blend ofpolyethylene and polypropylene.
 12. The flooring system of claim 9,wherein the at least one polyolefin layer is a non-cross-linkedpolyolefin foam that consists essentially of polyethylene.
 13. Theflooring system of claim 9, wherein the underlayment material includesat least one of an anti-microbial additive, a flame retardant additive,and an adhesion promoter.
 14. The flooring system of claim 9, wherein atleast one polyolefin layer is partially debossed.
 15. A method,comprising: placing an underlayment material between a subfloor and atop flooring layer, wherein the underlayment material comprises anon-skid surface for engaging the subfloor, the surface comprisingthermoplastic rubber.
 16. The method of claim 15, wherein thethermoplastic rubber provides a frictional resistance to movement forthe underlayment material relative to at least one of the subfloor andthe top flooring layer.
 17. The method of claim 15, wherein thethermoplastic rubber does not provide an adhesive resistance to movementfor the underlayment material relative to at least one of the subfloorand the top flooring layer.
 18. An underlayment material for placingbetween a subfloor and a top flooring layer, wherein the underlaymentmaterial comprises: a non-skid surface for engaging the subfloor, thesurface comprising thermoplastic rubber.
 19. The underlayment materialof claim 18, wherein the underlayment material comprises a film that hasbeen treated with the surface laminated to a foam layer.
 20. Theunderlayment material of claim 19, wherein the film is a polyethylenefilm or a polypropylene film.